Causes of right knee pain include trauma, rheumatoid arthritis, meniscus injuries, and ligament strains. Different causes of pain are examined in different ways. 1. If it is trauma that causes problems with the bones, CT or X-ray should be performed. CT and X-ray are more sensitive to the bones and can show the bone condition very well. 2. If there is meniscus injury, soft tissue problems around the knee (ligament strains, muscle injuries), or inflammation of the knee joint (rheumatoid arthritis, gouty arthritis), an MRI should be performed. The MRI can provide a better view of the soft tissue and meniscus. 3. Knee arthrography can be performed if there is a problem with the meniscus, ligaments or joint cavity, but this modality is not commonly used now and is gradually being replaced by MRI. It is recommended to seek medical attention for knee pain in a timely manner, and under the guidance of the doctor, relatively reasonable imaging tests should be performed so as to make a diagnosis and treatment plan.